Mining-machine chain link and bit



Dec. 22 1925. 1,566,304

N. K. BOWMAN Patented Dec. 22, 1925.

UNITED STATES 1,566,304 PATENT OFFICE.

NEWTON K. BOWMAN, b1 BOWDIL, OHIO.

lfINING-MACHINE CHAIN LINK AND BIT. I

Application filed November 6, 1922. Serial No. 599,316.

To all whom it may concern.

Be it known that I, NEw'roN K. BOWMAN, citizen of the United States, residing at Bowd-il, in the county of Stark and State of Ohio, have invented certain new and 'useful Improvements in Mining-Machine Chain Links and Bits, of which the following is a specification.

This invention relates to an. improved chain link and bit for mining machines and seeks, as one of its principal objects, to provide a link which will function to rigidly support the bit near the workin end theregf to prevent bending. or brea ing of the The invention has as a further objectto' provide a bit stock and ;;clamp of novel construction for detachably supporting a cutting tooth.

- And the invention has as a still further object to provide a device embodying an improved cutting tooth.

Other and incidental objects will appear hereinafter.

In the drawings: V

Figure 1 is a sectional view through my improved link and bit,

Figure 2 is a top plan view of the device,

Figure 3 is a fragmentary perspective view showing the abutment rovided for the bit at the outer end of the ink,

Figure 4 is a detail perspective view showing the stock, clamping bar and cutting tooth employed,

Figure 5 is a detail sectional view on the line 5-5 of Figure 1, looking in the direction of the arrows,

Figure 6 is a detail cross section taken medially through the cutting tooth employed, and

Fi ure 7 is a fragmentary'sectional view showlng a slight modification of the invention.

. In carryin the invention into effect, I employ alinc including a bod 10 having the usual eyes 11 so that the ink may be readily interposed in amining machine chain in the customary manner and formed in the link-is a recess 12 from the bottom of which leads a passage 13 opening through the inner end of the lmk. Projecting from the rear end wall of said recess near the bottom thereof is a shoulder-14 and threaded through the forward end wall of the recess is a set screw 15, the link body bein cut away at the ends of the bottom wa of the recess so as to avoid filled corners between said bottom wall and the end walls of the recess. Extending from the outer end of the link flush with the rear end wall of the recess is a lug 16 having side portions 17 lying flush with the side walls of the recess and, as particularly brought out in Figure 3, said lug is formed with an extension 18 projecting beyond said side portions.

In conjunction with the link I em loy a bit including a stock 19 which is ormed to snugly but removably fit in the recess 12 of the link abutting the rear end wall of said recess and, as brought out in Figures 1 and 3, said stock is cut away at its rear edge to define a lug or shoulder 20 at the lower endof the stock engaging beneath the shoulder 14 of the link limiting the stock against outward movement. Formed in the forward edge of the stock at its outer end portion is an arcuate seat 21 openin at one end through the forward edge of t e stock and at its opposite end through the outer end edge thereof. As shown in Figures 2 and 5, this seat is substantiallyV-shaped in cross section. Snugly but removably fitting in the recess 12 to confront the stock is a clamping bar 22. This bar is provided with a beveled outer end edge and formed in the forward edge of the bar at the outer end portion thereof is a V-sha ed kerf 23 gradually increasing in depth rom its .inner end toward its outer end to define diver 'ng bearing lugs 24 at the outer end of the liar.

Removably clamped betweenthe stock 19 and the clamping bar 22 is a segmental cutting tooth 25. This tooth is preferably formed from a bar of hardened steel square in cross section and curved on a line occupying a plane with diagonally opposite edges of the bar so that an arcuate edge 26 is thus presented at the rear side of the tooth. The radius of the tooth corresponds, of course, to the radius of the seat 21 of the stock so that the tooth rests flat in said seat and, at its .forward side, the ends of 'the toothare ground .ofi or cut away to define concave working faces 27 of less radius than the radius of the tooth and curving in opposite directions lon itudinally of the tooth to the ends thereof. gutting points are thus defined at the ends of the tooth, the tooth being accordingly rendered double-ended so that the tooth may be reversed end for end upon the stock and, as will be observedythe rear faces of the tooth are beveled at the ends thereof to provide sharp cutting edges diverging from'said cutting points. Between the working faces 27 is defined a saddle 28 and, as shown in Figure 5, the bearing lugs 24 of the clamping bar 22 snugly fit said saddle. Accordingly, by properly adjusting the screw 15, the tooth may be firmly clamped between said bar and'the stock, rigidly supported thereby,the outer end of the tooth extending beyond the outer end of the stock to engage the work and, in this connection, it is to be noted that the side portions 17 of the lug 16 extend outwardly along the side of the stock for bracing. the projecting outer end portion of the stock against side strain while the extension 18 of said lug projects outwardly at the rear edge of the stock for supporting the outer endof the stock against the thrust of the tooth. The outer end of the stock is thus effectually braced and it has been found in practice that said extension serves to prevent the breaking off or twisting of the stock at its outer end.

, In Figure 7 of the drawings, I have illustrated a slight modification of the invention wherein the link body is indicated at 29. The link body 29 is similar to the link body 10 of the preferred construction and is formed with a recess 30 at the rear end wall of which the link body is formed with a lug 31 having an extension 32 thereon,'as in the preferred construction. In the present modification, the portion of the link at the rear of the recess 30 is utilized to provide a stock for the cutting tooth and is accordingly formed with an arcuate V-shaped seat 33 corresponding to the seat 21 of the stock 19. The seat 33 is shaped to receivea cutting tooth 34 corresponding to the tooth 25 and coacting with the tooth is a clamping bar 35 corresponding to the bar 22. The link body carries a set screw 36 and, as will be seen, this set screw may be adjusted to coact with the bar 35 for clamping the tooth 34 in position. 7

Having thus described the invention, what is claimed as new is:

1. In a mining machine, a chain link, a stock carried thereby and provided with a concavely curved seat, a curved cutting tooth fitting said seat, and a clamping bar I having one face thereof notched to straddle stock carried thereby and provided with a concavely curved V-shaped seat, a curved cutting tooth fitting said seat and having its forward side cut away to define cutting points at the ends of the tooth as well as to define an intermediate saddle between said cutting points, and a clamping bar grooved to define bearing flanges straddling said saddle binding the tooth between said bar and stock.

4. In a mining machine, a double-ended cutting tooth square in cross section and curved longitudinally on a line occupying a plane with diagonally opposite edges of the tooth and having its ends cut away at the forward side of the tooth to define cutting points.

5. In a mining machine, a double-ended cutting tooth polygonal in cross section and curved longitudinally on a line occupying a plane with diagonally opposite edges of the tooth and having its ends cut away at the forward side of the tooth to define cutting points as well as to also define an intermediate V-shaped saddle between said points.

6. In a mining machine, a double-ended cutting tooth square in cross section and curved longitudinally on a line occupying a plane with diagonally o posite edges of the tooth and having its en s cutaway to define concave faces of less radius "than the tooth forming cutting points at the ends of the tooth. 1

7. In a mining machine, a solid cutting tooth having angularly disposed faces forming an edge at the back of the tooth, the tooth being curved longitudinally on a line occupying a plane between said faces with 105 said edge.

In testimony whereof I affix my signature.

NEWTON K. BOWMAN. r1. 5. 

